The suspect is 56-year-old Cesar Sayoc Jr., originally from Brooklyn and currently of Florida. Public records show he has a lengthy record of arrests for battery, theft, moving violations, and steroid-related charges -- as well as a 2002 incident where he threatened to throw a bomb. In that case, he was accused of telling a power service representative he was going to blow up the company and it would "be worse than 9/11." Sayoc pleaded guilty in that case and received probation.

A registered Republican, his social media accounts identify him as an ardent supporter of President Trump who attended many rallies -- and who continued tweeting about some of his targets even after the bombs started arriving. When he was arrested, authorities seized a van festooned with stickers of Trump and Vice President Mike Pence, as well as anti-Democrat and anti-media stickers (some overlaid with crosshairs).

Photo credit: NBC 6

Attorney General Jeff Sessions, at a Department of Justice news conference, said Sayoc would face five charges and up to 48 years in prison if convicted. According to sources, Sayoc was questioned under national security exception where he denied the charges before asking for a lawyer and refusing to answer further questions.

A 'VERY NICE' PERSON

A cousin who wished to remain anonymous told NBC News that Sayoc had been working in strip clubs since he was 22, as both a dancer and bouncer. In a 2014 court filing, Sayoc described himself as a road manager for traveling male "revues" during which dancers strip.

“He’s very estranged from his family," this cousin said, describing Sayoc as a "loner" with "a lot of problems."

As recently as Thursday night, Sayoc was working as a DJ at a strip club in West Palm Beach, NBC affiliate WPTV reported.

Another cousin of the suspect described Sayoc as a "very nice, thoughtful person." Asking not to be identified, the woman said she was stunned to hear about his arrest. She knew nothing about his political beliefs or arrest history, she said. The two hadn't connected in 20 years until recently, when her father died.

"It was mostly just small talk, how's your family, that kind of thing," the woman said. "I don't really know that much about him. We have a very big family."

His one-time defense attorney Daniel Aaronson described Sayoc as being "as polite of a client as I’ve ever represented" and said he would be willing to represent him in this case.

But not everyone had such nice things to say. A former TV reporter named Rochelle Ritchie tweeted that the suspect had previously threatened her life on social media accounts following a TV appearance.

The Seminole Tribe of Florida issued a statement denying Sayoc was a member or that he had worked at the tribe's Hard Rock casino, despite Sayoc's claims on social media to the contrary.

The arrest news followed shortly after the discovery of two more suspected mail explosives in New York City and in Florida, one addressed to former Director of National Intelligence James Clapper and one to New Jersey Sen. Cory Booker. After Sayoc's arrest, word emerged of another suspicious package sent to Sen. Kamala Harris in Sacramento.

14 BOMBS

The four parcels seized Friday bring the total number of suspected mail bombs to 14. All of the packages were irregularly shaped, in yellow manila envelopes, with six stamps that were not postmarked.

None of the bombs detonated, no injuries were reported and authorities said Thursday it appeared some of the devices were flawed and incapable of exploding, though it wasn't clear if they were purposefully structured that way or it was just bad construction.

According to sources, the explosive devices were made from PVC pipe and contained a timer (likely a digital alarm clock) to set off the detonator. The powder contained in the bombs comes from pyrotechnics. X-rays show there was likely shrapnel inside the PVC pipe, law enforcement officials say.

The return address listed on each one was the Florida office of ex-Democratic National Committee chair Rep. Debbie Wasserman Schultz. Investigators had said they were looking into any past incidents involving her office to determine if there could be any connections to the current probe, but have said there is no suggestion she had any involvement whatsoever.